Paediatrics: Hypertension: definition

Hypertension: definition

Defined by reference to sex, height centile charts (see Fig. 11.1).

·  Normal: systolic and diastolic <90th centile.

·  High normal: systolic or diastolic between 90th and 95th centile.

·  Hypertension: systolic or diastolic >95th centile.

·  Severe hypertension: systolic or diastolic >99th centile.

BP measurement should be part of routine examination.

Measurement technique

·  Cuff size.

·  bladder width—70% of acromion olecranon distance or 40%

o mid-arm circumference;

o bladder length—should completely encircle arm.

o Note: small cuff area is a common cause of false positive high BP!

·  After 5min rest (ideally!).

·  Sitting position with arm at level of heart (children).

·  Supine position in infants.

·  On auscultation: 1st and 5th (disappearance) Korotkoff sounds used for systolic and diastolic values, respectively.

Measurement devices

·  Manual oscillometric sphygmomanometer (mercury now withdrawn).

·  Doppler: infants (for systolic pressure).

·  Automatic oscillometry: not all devices suitable.

·  Ambulatory blood pressure monitoring (ABPM) for 24-hr profiles:

o little normative data in paediatrics;

o significant hypertension ≥30% readings above 95th centile.

·  Intra-arterial (in intensive therapy unit (ITU) setting).